Self-sustained phase-shift modulated resonant converters: modeling, design, and performance

This paper presents an improved control technique for the full bridge series, parallel, and series-parallel resonant converters. This control technique combines a self-sustained oscillation mode with a phase shift modulation technique that can significantly reduce the range of frequency variation necessary for obtaining zero voltage switching in the resonant converters. This frequency reduction provides optimized component ratings and operating frequency. A simple and accurate low order mathematical model based on the sampled data technique that fully describes the steady-state, and dynamic performance of the resonant converters, has been developed. A refinement algorithm is developed to enhance the accuracy of the modeling technique and the converter design. The improved converter performance and the feasibility of the developed dynamic model have been investigated using the series-parallel resonant converter topology with a capacitive output filter. Finally, MATLAB numerical solutions, PSIM simulation results, and experimental results are given to highlight the merits of the proposed work.